diff --git a/exercises/04_traits/05_trait_bounds/src/lib.rs b/exercises/04_traits/05_trait_bounds/src/lib.rs
index 10f0eb4..9327d86 100644
--- a/exercises/04_traits/05_trait_bounds/src/lib.rs
+++ b/exercises/04_traits/05_trait_bounds/src/lib.rs
@@ -6,7 +6,10 @@
 // collections (e.g. BTreeMap).
 
 /// Return the minimum of two values.
-pub fn min<T>(left: T, right: T) -> T {
+pub fn min<T>(left: T, right: T) -> T
+where
+    T: Ord,
+{
     if left <= right {
         left
     } else {